FLAC is a free lossless compressed audio format which supports streaming and archival. The FLAC project maintains the format and provides a reference encoder/decoder and input plugins for several popular audio players.

Jahshaka is a video and film compositing, editing and special fx system that uses OpenGL & OpenML hardware rendering to give operators real time interactivity. The system is cross platform, and also includes full CG, paint and image processing modules.

The Pure Data (short Pd) project on SourceForge unifies the extensions (or externals) written for the Pure Data Graphical Computer Music System written by Miller Puckette with contributions from many others.

MAD is a high-quality fixed-point MPEG audio decoder with 24-bit output. The implementation is entirely new, based on the ISO/IEC standards, and performs especially well on systems without native floating-point support.

ZynAddSubFX is a powerful realtime, multi-timbral software synthesizer for Linux and Windows. It is microtonal, and the instruments made by it sounds like those from professional keyboards. The program has effects like Reverb, Echo, Chorus, Phaser...